Water plants deeply and early in the morning. Most plants
need approximately 1 to 2½ inches of water per week.

Providing birdbaths, shelter and food will help turn your
landscape into a backyard wildlife habitat.

Insect identification is important so you don’t get rid of
the “Good Guys.” (EPP-7307)

The hotter and drier it gets, the larger the spider mite
populations!

Expect some leaf fall, a normal reaction to drought. Water
young plantings well.

Watering the Yard and Garden Efficiently

David Hillock

During the summer, watering the landscape and garden can be
the primary focus of our activities. Irrigation systems, whether a simple
hose-end sprinkler or an elaborate in-ground system, help us accomplish this
great task with a little more ease. Obviously some systems require a little
more attention and effort than others. However, all should be closely monitored
and managed so that they are working efficiently and providing adequate
coverage for the plants’ needs.

A minimum of one inch of water per week is usually required
to maintain optimum growth of most plants. However, that will vary depending on
the types of plants grown, the soil type, and weather conditions. During the
hottest and driest part of the summer, two or more inches per week may be
necessary. But, how much water does your sprinkler(s) put out?

One way to find out how much water your system is
discharging is to catch the water. Use straight-sided canisters such as tuna
cans and place them randomly under the sprinkler pattern. About six cans work
well. Turn the sprinkler(s) on and let them run for about 15 minutes. Turn off
the water and measure the depth of water caught in each can using a simple
ruler. Average all the measurements together and this will tell you how much
the system is discharging and how long to run the sprinkler system. For
example, you wish to place one inch of water when you irrigate. The average
amount of water that was measured when running the system for 15 minutes was
.25 inches. So, you will need to run your system for one hour in order to
irrigate one inch.

Some plants require constantly moist soils to maintain
optimum growth and performance while others are quite drought tolerant and
might even prefer drier soils. One way to make sure all the plants in the
landscape are getting what they need is to group plants together based on their
watering needs. Be careful not to plant together two plants that have
completely different water needs or one of them will eventually suffer and die.

Brown Patch Disease of Cool-Season Grasses

David Hillock

Brown patch is a disease that commonly shows up on cool-season
turfgrasses, especially tall fescue, but can occasionally appear on hybrid
bermudagrass and zoysiagrass. Brown patch disease appears as brown patches up
to three feet in diameter. Leaves first take on a dark color, then wilt and
turn brown.

Brown patch usually occurs in hot, humid weather when night
temperatures are above 60°F and foliage remains wet for prolonged periods. Poor
soil drainage, lack of air movement, cloudy weather, heavy dew, overwatering
and watering in late afternoon favor prolonged leaf wetness and increased
disease severity. The application of high rates of nitrogen and or deficiencies
of phosphorus and potassium, especially when weather conditions are favorable
for brown patch, can increase disease severity. Excessive thatch, mowing when
wet and leaf fraying by dull mower blades can also enhance the severity of
brown patch.

Control starts with good management practices. Though there
are varieties of turf-type tall fescue that are considered resistant to brown
patch, even resistant varieties succumb when growing conditions are less than
ideal for growth of strong plants (as described above) and environmental
conditions are highly favorable for disease development.

When environmental conditions favor disease, avoid
application of excessive rates of nitrogen. Fertilizer should be applied
judiciously, and adequate amounts of phosphorus and potassium are essential to
ensure the highest possible levels of plant resistance. In general, cool-season
turfgrasses should not receive more than one pound of actual nitrogen per 1,000
square feet at any one time. Use very low rates or avoid applying nitrogen in
late spring or summer to cool-season turfgrasses. In a typical home lawn
situation, the last application of fertilizer in the spring should be applied
no later than early May. Ensure adequate amounts of phosphorus and potassium by
applying these nutrients based on soil test results.

Reduce prolonged leaf wetness by watering infrequently to a
depth of 6 to 8 inches and at a time when the foliage is likely to dry quickly.
Avoid watering in late afternoon and evening, and allow for better air movement
by removing unwanted vegetation and selectively pruning trees and shrubs.
Removal of morning dew reduces prolonged leaf wetness and exudates that favor
disease development. This can be accomplished by dragging a hose across the
turfgrass or by running the irrigation system for a short time period. Good
surface and soil drainage must be present to reduce disease incidence.

Make sure mower blades are sharp to reduce the amount of
wounded turfgrass in which the fungus can enter the plant. Collect and promptly
dispose of clippings on infected areas or when conditions favor disease
development. Avoid mowing turfgrass when wet, and do not mow too low so that
the turfgrass will be better able to resist the disease.

Applications of effective fungicides, when the first disease
symptoms appear, will give good control of brown patch on highly maintained
turfgrass. A preventative fungicide program should be considered in areas where
the above conditions are difficult to control or change and when conditions are
favorable for disease development.

Dividing and Replanting Iris

David Hillock

Irises are relatively carefree, easy to grow and long lived
perennials; however, they should be divided every three to four years when they
become crowded. Crowded iris will begin to decline in growth and will have
fewer and smaller flowers.

Divide the rhizomes (underground stems) after the plants
have flowered; July through August is the best time to do this in Oklahoma.
Throw away any segments that are diseased, riddled with insects, or small and
weak. Separate healthy rhizomes into segments with one fan of leaves and
several roots. Cut the leaves back to six inches. When planting the new plant,
spread the roots out in the soil and position the top of the rhizome at the
soil surface. If planted too deep they will not flower as well and are more
susceptible to disease and insect attack.

Diagnosing Problems in the Landscape and Garden

David Hillock

Throughout the growing season a number of problems can arise
in the landscape and garden. The County Extension Offices throughout the state
as well as your local garden professionals are a good source in helping
diagnose the problem. The County Educators and garden professionals are trained
to look for and ask certain questions to help narrow in on the problem. Knowing
some of the things they will be looking for will help you possibly diagnose the
problem yourself or be better prepared with the information they will need to
solve the dilemma. Here are some of those areas to consider.

Keep an
open mind. Do not jump to conclusions.

Avoid
assigning “Guilt by Association.” The insect, animal, or disease observed may
not be the actual cause of the problem or symptom.

Take a
thorough history: weather extremes, site alterations, fertilizer and pesticide
use, cultural practices, etc. Once mature trees (especially pines and oaks)
begin to decline, there is often no way to reverse the process.

The
symptom may indicate a problem in a different part of the plant. Example, brown
leaves may be the result of a root problem or trunk or stem damage.

Know
what the healthy plant should look like.

At
least one half of all observed landscape problems are not caused by insects or
diseases. Try to eliminate other causes first.

A
particular problem may be caused by several factors.

There is
a great variation in the expected life-span of landscape plants. All plants go
through periods of growth, maturity and decline. Plants grown in urban
locations generally have shorter lives.

Many
pests and diseases are plant specific. Symptoms affecting more than one plant
species may indicate cultural and environmental problems.

There are many other areas to consider and questions that
may need to be asked. Be prepared to answer questions to the best of your
ability. Remember, we can never ask enough questions. The more thorough you are
the better the diagnosis will be!

New Invasive Blackberry Pest for Oklahoma – Broad Mites

Becky Carroll

Please ask your blackberry growers if they’ve had symptoms
like the following pictures.

Starts as leaf cupping on primocanes.

Then see delayed bud break or weak or dead floricanes.

This damage is caused by Broad Mites. They were first
confirmed in Oklahoma blackberries in May of this year. They had been seen in
Arkansas on primocane fruiting berries since 2006 and now about 10 other states
have reported damage. Since this is the first sighting on blackberry in
Oklahoma, we need to determine how widespread the pest is in the state. If you
have growers with similar damage, please let me know so we can get samples to
the diagnostic lab for identification. More information is available in the
following link to a Pest e-Alert from Dr. Eric Rebek on Broad Mites on Blackberries
that was published recently. http://entoplp.okstate.edu/pddl/2017/PA16-28.pdf.

Upcoming Events

Cimarron Valley Research Station
Horticulture Field Day Part II – August 1

Want to know what is going on at the Cimarron Valley
Research Station with horticultural crops? Make plans to attend the scheduled
Horticulture Field Day on August 1, 2017 from 1 to 4 p.m. This tour and
field day will be similar to the May field day that was held but a new batch of
crops will be toured and discussed. Please meet at the North entrance on 104th
Street just north of Perkins. There is no charge for event. Participants will
get to tour and learn about pumpkins, cow peas, grapes, pecan crop load thinning
and other horticultural crops.

Current Challenges in Floriculture – Shackelford Lecture
Series, August 3

The Current Challenges in Floriculture Conference will be
held on Thursday, August 3, 2017 at the Wes Watkins Center in Stillwater, Oklahoma.
A variety of topics, taught by both academics and industry leaders, will be
highlighted at this year’s conference. Although an overview of
floriculture issues and challenges will be discussed, water quality and
quantity will be emphasized by one of the keynote speakers, Dr. Genhua Niu,
Texas A&M, El Paso. The conference is designed to interest both the
commercial grower/retailer as well as gardening enthusiasts. Pesticide
applicators may also find this event useful as ODAFF CEUs in categories 3 and
10 will be offered. Registration is $30 per person and includes lunch. For
more information, please visit www.hortla.okstate.edu.

Fall Pecan Field Day Set for September 22

Knight Creek Farms near Sapulpa will host an upcoming field
day for interested pecan growers. This free event will showcase topics like
early pecan harvest and drying operations; row harvesting; new planting and
irrigation options; wildlife control options; and marketing.

The field day is scheduled to begin at 2 p.m. on Friday,
September 22 and dinner will begin at 6 p.m. sponsored by Grissoms John
Deere. More information and directions will be available soon for this event
presented by Oklahoma State University, Noble Research Institute and Oklahoma
Pecan Grower’s Association.

Viticulture & Enology Workshop Scheduled October 24

A special workshop will be held at Waddell’s Vineyard &
Winery near Ada on October 24. Registration for the event will begin at 8:30 a.m.
and the presentations will commence at 9 a.m. Featured speakers from Texas
AgriLife Extension program include Dr. Justin Scheiner and Michael Cook.

Dr. Scheiner will be making a return appearance to share
expertise on many applicable topics for our Oklahoma growers. He was a favorite
presenter at a 2014 advanced training workshop. Michael Cook is located out of
Denton, Texas and has been spending some quality time in some of our Oklahoma
vineyards lately. He has provided consultations to vineyards that had requested
site visits through an Oklahoma Grape Industries Council grant. The OGIC grant
as well as the grant for this workshop was made possible through the ODAFF
Viticulture & Enology Fund.

Some possible topics for the day’s workshop include Grape
Cultivar Selection, Fruit & Foliar Diseases, Understanding Vineyard
Fungicides, and Grapevine Nutrition. Many of the topics will address challenges
that vineyards are encountering as observed by Michael Cook on his site visits.
This will be an excellent learning opportunity and will benefit all grape
growers. An agenda will be available soon with more details on how to register
for this free workshop. Lunch will be catered so an accurate count of those
planning to attend will be helpful.

SAVE THE DATE – March 8, 2018 for a Horticulture “Spray Day”

A new horticultural event is in the planning stage that will
be focusing on spraying, including fungicide, insecticide, and herbicides. This
event will be held at the Cimarron Valley Research Station and open to anyone
interested. Emphasis will be on equipment demonstrations for different crops
and different sizes of operations; question and answer times; sessions on
calibration, worker protection standards, pesticide certification requirements
and pest management. We hope to have
vendors with different types of equipment and chemical representatives in
attendance. Sponsored by Oklahoma State University Horticulture & Landscape
Architecture Department, Oklahoma Field Research Service Unit, Noble Research
Institute, Oklahoma Pecan Growers, Oklahoma Grape Industries Council, and
Oklahoma Fruit & Vegetable Growers.